Ionized gas outflows and shock-heated emission in the highly inclined active galaxy CGCG 012-070

Abstract

Active galactic nuclei (AGNs) exhibit excess mid-infrared H2 emission compared to star-forming galaxies, likely driven by outflows and shocks inferred from integrated spectra. We present optical IFU (integral field unit) observations of the central 2 kpc of the AGN host CGCG 012-070, selected for its pronounced H2 emission excess, to map stellar and gas kinematics. The stellar velocity field is well described by a rotating disc with a line of nodes at 103◦ ± 4◦, with the north-west side approaching and the southeast side receding. Gas kinematics, traced by strong emission lines, show two components: a narrow one (σ 200 km s−1) in the disc plane following stellar motions, and a broad (σ 300 km s−1) associated with outflows within the inner ∼1 kpc. Disc gas emission is mainly driven by AGN photoionization, while the outflow also includes shock-heated gas, as indicated by flux ratio diagnostics. The outflows are radiatively driven, with a mass-outflow rate of (0.067 ± 0.026) M yr−1 and a kinetic coupling efficiency of 0.07 per cent, potentially redistributing gas and contributing to maintenance-mode feedback in CGCG 012-070. Our results provide further evidence that the warm H2 emission excess in nearby AGN is associated with shocks produced by outflows. Observations of other gas phases, such as cold molecular gas, are necessary to gain a more comprehensive understanding of the impact of the outflows on the host galaxy.